Clinical features and long-term outcomes of bilateral Wilms tumor treated with Taiwan Pediatric Oncology Group protocols: A single center report

Aims: Wilms tumor (WT) is rare in Asia. Treatment of bilateral WT is challenging, and the treatment outcome of bilateral WT is rarely reported in low incidence areas. Methods: We enrolled patients with bilateral WT registered in Chang Gung Memorial Hospital, Taoyuan, Taiwan, between January 1986 and June 2015. They were treated according to the Taiwan Pediatric Oncology Group (TPOG) protocols. The clinical features and long-term outcomes were analyzed. Results: Six patients with histologically-proved bilateral WT were identified for analysis. One additional patient who was diagnosed with unilateral WT-associated intralobar nephrogenic rest, in addition to two small lesions in the contralateral kidney, was also included. There were total of three male patients and four female patients. The median follow-up period was 19 years (range 8–29 years). Five patients underwent initial biopsy and preoperative chemotherapy followed by surgery, whereas two patients underwent initial surgery followed by adjuvant chemotherapy. Local recurrence was found in two patients. The 8-year event-free survival and overall survival rates were 71.4% and 100%, respectively. Two patients developed advanced stage of chronic kidney disease, but none had been diagnosed with secondary malignant neoplasm. Other health issues such as hypertension, scoliosis and unspecified autoimmune disease were also found. Conclusions: The treatment outcome in this study is comparably superior to other western countries. However, survivors of bilateral WT still have many chronic health issues and thereby need individualized long-term medical care.